An IR spectroscopic method of determining the presence or absence of metallic material embedded in polymer material including irradiating a surface of said polymer material and collecting at least one spectrum of reflected infrared energy from said surface of said over a spectrum of wavelengths including the near-infrared wherein said metallic material is at least partially absent in a affected condition; performing a multivariate comparison of said at least one spectrum with at least one reference spectrum to determine a change in reflectance of said at least one spectrum with respect to at least one reference spectrum wherein said metallic material is present in an unaffected condition; and, correlating the amount of said change in reflectance with the presence or absence of said metallic material embedded in said polymer material.